PCI-5122 Unregistered error -218802

[Hanno Homann]

Hi,

I am using the digitizer PCI-5122 (256 MB / channel) with Labview 8.2, NI-Scope 3.4 and windows XP.
Starting off with the NI example "niScope EX Multi Record Fetch More Than Available Memory.vi"
everything was running fine first, but now I encounter a problem with the following configuration:

sample rate: 20 MHz
external trigger (to start a record): 20 kHz
min record length: any (I tried 1 or 1000)
number of records: larger than 105,000 (the error does not occur for values < 100,000)

The error message reads as follows:
> Error occurred at:  niScope Multi Fetch Cluster.vi:1
> <err>Driver Status:  (Hex 0xFFFCA94E)
> Unregistered error -218802 occurred:
> No error occurred.
>
> Component Name: nimxslu proxy
> File Name: This is NOT an error in nimxslu. See nimxsl/tStatus2KernelProxyWrapper.cpp for information
> Line Number: 290
> Status Code: -218802

Do you have any suggestions how to solve this problem? I need to acquire many more records
and also will need to use the "records > available memory" function later on.

Many thanks,
Hanno

[TobiD]

Hi Hanno,

The cause of this error is actually unrelated to its message. When acquiring a record of data into onboard memory, the record's timestamp must also be stored. There is a finite buffer on the host for these timestamps, and it can only hold 100,000 values. If the board attempts to store more than 100,000 records at once, an error will occur from the overwrite attempt.

The solution to seeing this error is to use the timestamps on the host before they are overwritten. You can:

• Fetch records while the acquisition is in progress
• Fetch more records at a time, so that fewer are left in onboard memory after each fetch
• Decrease the trigger rate so that records can be fetched before their timestamps are overwritten. If the trigger is not under your direct ontrol, you can use the "Trigger Holdoff" property to throttle the trigger rate.
  

regards,
Tobias

[Hanno Homann]

To fetch more records at a time solved my problem, thanks a bunch Tobi 🙂

For anyone else who comes along this problem: Remember also to increase
the parameter "Fetch record number" inside the while loop of the NI example
by "Fetch number of records" at every iteration.

Cheers,
Hanno